The present invention concerns a method and an apparatus for displaying network numbers of users involved in a connection on a display associated with a device in a communication network.
Network numbers, e.g. telephone numbers, in the United States usually have a 3-level numbering plan structure with a first level, e.g. local number, a second level regional number, e.g. national number, and a third level complete number, e.g. international number. Some digital communication networks like an ISDN, and also some analog networks are capable of displaying the number of an incoming call on a device with a display.
The preferred embodiment of the present invention is described in terms of an apparatus and method for displaying network numbers in a private communication network, although the same concepts can be applied to other network addresses and applications. Numbering and sub-addressing in private ISDNs, for example, is well known and is standardized by ISO/IEC DIS 11571, ETS 300 189 and ECMA 155. The standards prescribe a hierarchically organized 3-level structure of Private Numbering Plans (PNP) and allow for both implicit and explicit numbering schemes.
Standards also dictate that, when two switches are in different regions for a given region level, the switch (also called a Private Telecommunication Network/Exchange (PTN/X) or private branch exchange (PBX)) sending a number must send a region number for that region level to the other switch, to avoid number ambiguity. Instead of sending just a lower region level number, the switch must convert the number into a region number of a higher level by adding the appropriate complete/regional number and changing the Type of Number (TON) accordingly. This means that switches ultimately must always send the highest level number to another switch since the call has the potential of leaving the region for any particular region level at any time during the life of the call, e.g. when the call is transferred to a different region level.
As a result, existing network systems that can display the number for an incoming call generally display the entire number. While the requirement of sending higher level region numbers is absolutely necessary, the user interface suffers with displays of very long numbers, resulting in truncation of feature messages like the user name display. Secondly, recognizing and remembering long numbers is more difficult than short numbers.